Relocate boot component in physical memory to be adjacent to kernel

[gparmer]

Currently, GRUB tends to place the boot component into physical memory significantly offset from the end of the kernel. There is, as far as I can see, very little reason for this offset.

This proposal is to mem_move (note we can't memcpy) the booter to be physically contiguous with the kernel memory during the early boot process (i.e. modifications in kernel.c) while updating where the boot-time dynamic allocations, and untyped memory are located. These will overlap with the current boot component memory, so it will likely need to be zero-ed out. This will reclaim around 10MB-50MB of memory which is lost for no real reason.

[georgit]

Sounds good. Are there any obstacles to this?

[gparmer]

Not really. It is a straightforward change as far as I can tell, but one that is lower priority at this point than other things (tcaps, embedded VM, cbufs on Speck, etc...).

BTW, in the above, I certainly meant memmove. My mistake.